Here is the full list of all 21 Sliding Puzzle Collection achievements.
Complete your first puzzle
Complete your first puzzle without using hints
Complete first bronze puzzle
Complete first bronze puzzle without using hints
Complete all bronze puzzles
Complete all bronze puzzles without using hints
Complete first silver puzzle
Complete first silver puzzle without using hints
Complete all silver puzzles
Complete all silver puzzles without using hints
Complete first gold puzzle
Complete first gold puzzle without using hints
Complete all gold puzzles
Complete all gold puzzles without using hints
Complete first platinum puzzle
Complete first platinum puzzle without using hints
Complete all platinum puzzles
Complete all platinum puzzles without using hints
Complete all puzzles
Complete all puzzles without using hints
Earn all achievements